Wound closure device

ABSTRACT

A wound closure device for positioning within a wound gap defined between at least two tissue segments has an effect of drawing the at least two tissue segments to a state of proximity that closes the wound gap. The wound closure device includes a tubular collapsible member having an expanded configuration and a collapsed configuration. The wound closure device further includes tissue engaging structure for attaching the tissue segments to the tubular collapsible member.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of and priority to U.S.Provisional Application Ser. No. 61/428,301 filed on Dec. 30, 2010, theentire contents of which are incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates generally to surgical fasteners andparticularly relates to a wound closure device to be inserted into awound gap between tissue segments to close the wound gap byapproximating the tissue segments.

2. Description of Related Art

A puncture wound is caused by an object piercing skin and subcutaneoustissue, and creating a hole therein. A surgical wound is an incisionthrough skin and subcutaneous tissue made during surgery. In order tominimize scarring, prevent infection and speed recovery time, woundclosure devices are typically used at the wound site to close the woundgap. Typical wound closure devices include sutures, staples and adhesivetapes. Each of the above devices has its own drawback. Morespecifically, suturing is a time consuming process and requires greatdexterity to properly close the wound. With respect to the use of astaple as a wound closure device, it may be difficult to apply staplesto the internal surfaces of a wound, such as a deep puncture wound. Fora similar reason, it also may be difficult to apply an adhesive tape tothe internal surfaces of a wound.

Thus, there is a need for a wound closure device that provides a simpleand fast approach for deployment in a wound, such as a deep puncturewound, to accelerate rehabilitation and provide optimal efficiency inclosing the wound internally and externally.

SUMMARY

Disclosed herein is a wound closure device for closing a wound gapdefined by at least two tissue segments. The wound closure device of thepresent invention comprises a tubular collapsible member defining aproximal end, a distal end, a longitudinal axis and a hollow boreextending along the longitudinal axis between the proximal and distalends. The wound closure device further comprises a tissue engagingstructure supported on an outer wall of the tubular collapsible memberpositioned to engage the at least two tissue segments. The tubularcollapsible member defines a first configuration in which the hollowbore is open. Additionally, the tubular collapsible member defines asecond configuration in which the hollow bore is substantially closed.Further, the tubular collapsible member is selectively movable from thefirst configuration to the second configuration to draw the at least twotissue segments towards each other such that the wound gap issubstantially closed.

In one embodiment, the tubular collapsible member is fabricated from ashape memory material that enables the member to possess a temporaryshape and a permanent shape. Specifically, the first configuration ofthe member corresponds to the temporary shape, whereas the secondconfiguration of the member corresponds to the permanent shape.

In a certain embodiment, the tissue engaging structure comprises aplurality of barbs configured to penetrate the at least two tissuesegments. The plurality of barbs define a first angle with respect tothe longitudinal axis of the tubular collapsible member beforecontacting the at least two tissue segments, and define a second anglewith respect to the longitudinal axis upon contacting the as least twotissue segments when the tubular collapsible member enters the wound gapin an insertion direction. The plurality of barbs resume the first anglewith respect to the longitudinal axis upon an application of force in adirection opposite to the insertion direction.

In another embodiment, the tubular collapsible member is operativelyconnected to a vacuum such that the vacuum facilitates transiting thetubular collapsible member from the first configuration to the secondconfiguration.

In an alternate embodiment, the wound closure device comprises a suturedisposed in the tubular collapsible member. An application of force onthe suture effects movement of the tubular collapsible member from thefirst configuration to the second configuration.

DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will become more apparent in light of the following detaileddescription when taken in conjunction with the accompanying drawings inwhich:

FIG. 1A is an isometric perspective view of a wound closure device inaccordance with the principles of the present disclosure illustrating atubular collapsible member in a first, expanded configuration;

FIG. 1B is an isometric perspective view of the wound closure device ofFIG. 1A in a second, collapsed configuration;

FIG. 1C is a side view of a barb associated with the wound closuredevice of FIG. 1A;

FIG. 2A is a front perspective view of the wound closure device of FIG.1A placed above a wound gap;

FIG. 2B is a schematic view of the barb of the wound closure device ofFIG. 2A illustrating its orientation relative to a longitudinal axis ofthe device;

FIG. 3A is a front perspective view of the wound closure device of FIG.1A as it is inserted into the wound gap;

FIG. 3B is a schematic view of a barb of the wound closure device ofFIG. 3A in a straightened position;

FIG. 3C is a schematic view of a barb of the wound closure device ofFIG. 3A in a flexed position;

FIG. 4 is a front perspective view of the wound closure device of FIG.1A fully deployed in the wound gap with barbs remaining in the flexedposition;

FIG. 5 is a front perspective view of the wound closure device of FIG.1A fully deployed in the wound gap with barbs in the straightenedposition;

FIG. 6 is a front perspective view of the wound closure device of FIG.1A in its second, collapsed configuration while fully deployed in thewound gap;

FIG. 7A is a front perspective view of an alternate embodiment of thewound closure device with a suture attached thereto;

FIG. 7B is a front perspective view of the wound closure device of FIG.7A deployed in the wound gap;

FIG. 7C is a front perspective view of the wound closure device of FIG.7A in the second, collapsed configuration;

FIG. 7D a front perspective view of the wound closure device of FIG. 7Cdeployed in the wound gap;

FIG. 8A is a front perspective view of another alternate embodiment ofthe wound closure device in the first, expanded configurationoperatively connected to a vacuum; and

FIG. 8B is a front perspective view of the wound closure device of FIG.8A in the second, collapsed configuration.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure will be describedherein with reference to the accompanying drawings. As shown in thedrawings and as described throughout the following description, and asis traditional when referring to relative positioning on an object, theterm “proximal” or “trailing” refers to the end of the apparatus that iscloser to the user and the term “distal” or “leading” refers to the endof the apparatus that is farther from the user. As used herein,“penetrate” refers to entering a layer of the skin without necessarilypassing completely therethrough, whereas “pierce” refers to entering alayer of the skin by completely passing therethrough. In the followingdescription, well-known functions or constructions are not described indetail to avoid obscuring the present disclosure in unnecessary detail.

The presently disclosed device described herein may be used to close apuncture wound, a surgical wound or other types of wounds that mayrequire simple and efficient closure.

Referring now to the drawings, in which like reference numerals identifyidentical or substantially similar parts throughout the several views,FIGS. 1A-1B illustrate a wound closure device 10 comprising a tubularcollapsible member 100 in accordance with the principles of the presentdisclosure. The tubular collapsible member 100 is adapted for insertionwithin a wound gap defined between at least two tissue segments and willbe described in greater detail below.

With reference to FIGS. 1A-1B, the tubular collapsible member 100defines a longitudinal axis “L”, and includes a proximal end 110, adistal end 120, an outer wall 111 and an inner wall 112. The inner wall112 of the member 100 defines a hollow bore 140 extending along thelongitudinal axis “L” between the two ends 110 and 120. The tubularcollapsible member 100 includes a tissue engaging structure 130extending radially outwardly from the outer wall 111. In one embodiment,the tissue engaging structure 130 extends outwardly in a proximaldirection from the outer wall 111 of the tubular collapsible member 100.The tissue engaging structure 130 is configured to penetrate tissuesegments at the wound site to safely anchor the tubular collapsiblemember 100 at the wound site and securely attach the tissue segments tothe outer wall 111 of the tubular collapsible member 100. The tissueengaging structure 130 may be in the form of a plurality of barbs 130,which are selectively positioned along the length of the member 100between the proximal end 110 and the distal end 120. Additionally, theplurality of barbs 130 may be placed to circumferentially surround theouter wall 111 of the member 100, and may be configured to have auniform length or various lengths.

In one embodiment, as seen in FIG. 1C, each barb 130 comprises aslender, lengthy body 131 with a first end rooted in the outer wall 111of the tubular collapsible member 100, and a second end with a head 132mounted thereto. As shown in FIG. 1A, the second end locates not onlyradially outwardly with respect to the first end, but also locates moreproximally as compared to the first end. The head 132 defines a radialdiameter substantially greater than that of the body 131. The slenderprofile of the body 131 reduces friction encountered by the barb 130during its penetration into the tissue segment thereby expediting thepenetration process. Further, the slender profile of the body 131reduces stress experienced by the tissue segment thereby reducing anypain that might be experienced by the patient. The relatively largerradial profile of the head 132 permits the head 132 to hook or graspsurrounding tissue to prevent the tissue from slipping off the head 132with an effect of securely attaching the tissue to the tubularcollapsible member 100. Alternately, other barb configurations areenvisioned.

Referring again to FIG. 1A, in one embodiment, a plurality of barbs 150are positioned at the proximal end 110 of the member 100. Each barb 150also has a body and a head as described with respect to the barbs 130.Alternately, other barb configurations are envisioned. The barbs 150stem from the inner wall 112 of the member 100 and extend radiallyinwardly towards the center of the hollow bore 140. As shown in FIG. 1A,the barbs 150 are all placed along one side of the inner wall 112 andare configured to grip or engage the opposing side of the inner wall 112when the two sides of the inner wall 120 meet. Alternately, barbs 150may be positioned along the longitudinal length of the inner wall 112,along any portion of the length, or at selected locations along thelength of the inner wall 112. In another alternate embodiment, barbs 150may be replaced with other means for securing opposing surfaces of theinner wall 112 together, e.g., adhesive.

The tubular collapsible member 100 defines a first configuration inwhich the member 100 is in a fully expanded state and has a maximumprofile as seen in FIG. 1A. In the first configuration, the hollow bore140 defines a maximum diameter, achieving a maximally expanded state. Inaddition, the tubular collapsible member 100 defines a secondconfiguration in which the member 100 is in a substantially deflated orcollapsed state and has a minimum profile as illustrated in FIG. 1B. Inthe second configuration, the inner wall 112 of the member 100 collapsesagainst itself, and substantially or entirely diminishes the hollow bore140. Also, in the second configuration, as the inner wall 112 iscollapsed to the second configuration, the barbs 150 securely engage theopposite side of the inner wall 112 to retain the member 100 in thecollapsed state.

The application of the wound closure device 10 to a wound site isexplained with reference to FIGS. 2A-6. With reference to FIG. 2A, thewound site comprises a wound gap “G” formed between tissue segments “T1”and “T2.” The wound closure device 10 in its first, fully expandedconfiguration is placed directly above the wound gap “G” before itsdeployment therein. Before contacting the tissue segments, the barbs 130are in an unstressed or unbiased condition, i.e., a straightenedposition. In the straightened position, all barbs 130 project outwardlyand proximally from the outer wall 111 of the member 100. Morespecifically, in the straightened position, as illustrated in FIG. 2B,each barb 130 forms an acute angle “θ1” with respect to the longitudinalaxis “L”. Due to the proximal orientation of the barbs 130, the barbs130 minimize potential friction that may be otherwise encountered duringthe insertion process of the member 100 thereby making the member 100compilable for distal insertion into the gap “G”.

With reference to FIG. 3A, to insert the device 10 into the wound gap“G”, the distal end 120 of the member 100 is positioned adjacent to anopening of the wound gap “G”, and a distal force “F1” is applied to themember 100. As the member 100 moves into the gap “G”, barbs 130 arebiased inwardly against the outer wall 111 of the member 100 as theyengage the tissue segments “T1” and “T2”. For instance, as shown in FIG.3C, a barb 1302 which has engaged the tissue segment “T2” is bentradially inwardly forming an angle “θ2” with respect to the longitudinalaxis “L.” The angle “θ2” of the stressed condition is less than theangle “θ1” of the unstressed condition, and may approach 0°. As seen inFIG. 3A, although the barb 1302 is in contact with the tissue segment“T2”, the barb 1302 does not penetrate tissue segment “T2” duringinsertion of the member 100 into the gap “G”.

The force “F1” is continuously applied to the device 10 until the member100 is fully deployed in the gap “G” to the extent as shown in FIG. 4,where the proximal end 110 of the member 100 is distally beneath thesurface “P1” of the wound opening. When the member 100 is fullydeployed, the member 100 in its entirety is positioned within the gap“G”, and all barbs 130 are in the flexed position in contact with thetissue segments, but have not penetrated the tissue segments.

After the member 100 is fully deployed as illustrated in FIG. 4, aproximal force “F2” is applied to the device 10 to lift the device 10 ina proximal direction until the proximal end 110 of the member 100reaches the surface “P1” of the wound opening, such that the surface“P2” of the proximal end 110 of the member 100 is coplanar with respectto the surface “P1” of the wound opening as illustrated in FIG. 5. Asthe member 100 moves proximally, the tissue segments “T1” and “T2” exerta force in a distal direction upon the barbs 130, causing the body 131and the head 132 of the barbs 130 to move distally relative to themember 100, thereby returning the barbs 130 from their flexed positionsto their straightened positions. As each barb 130 become fullystraightened, its body 131 extends and penetrates into the tissuesegment, and its head 132 grasps the tissue segment and securelyattaches the tissue segments “T1” and “T2” to the member 100. Becausethe barbs 130 are placed along the length of the member 100, the entirelength of the member 100 is thus able to engage tissue segments “T1” and“T2”.

After the barbs 130 are engaged with the tissue segments “T1” and “T2”,the member 100 is moved from its first, expanded configuration to itssecond, collapsed configuration as shown in FIG. 6, by the applicationof an external force, e.g., vacuum, or due to the inherentcharacteristics of the material used to construct the member 100, e.g.,shape memory material. In the second, collapsed configuration, the innerwall 112 closes upon itself substantially diminishing the hollow bore140. The barbs 150 or alternate structure located at one side ofselected locations of the inner wall 112 engage the opposing side of theinner wall 112 to retain the member 100 in the collapsed configuration.This transition brings the tissue segments “T1” and “T2” to a degree ofproximity that reduces and substantially closes the wound gap “G”. Byallowing the entire length of the member 100 to engage tissue segments,tissue segments are maintained in close approximation along the lengthof the wound to facilitate healing.

Please note that features described above with respect to the tubularcollapsible member 100 and the tissue engaging structure 130 also applyto all embodiments of the wound closure device 10 described below.

In one embodiment, the device 10 is fabricated, at least in part, from aresilient, semi-resilient, compressible, and flexible type material thathas sufficient compliance to form a seal against tissue segments. In oneembodiment, the device 10 is made, at least in part, from shape memorypolymeric materials which enables the device 10 to possess a permanentshape and a temporary shape. The first, expanded configuration of thedevice 10 represents its temporary shape, whereas the second, collapsedconfiguration of the device 10 represents its permanent shape. Asspecifically shown in FIGS. 1A-1B, in its first configuration or itstemporary shape, the device 10 extends radially outwardly from a plane“B” indicated by dotted lines “B1”, “B2”, “B3” and “B4”, whereas in itssecond configuration or its permanent shape, the entirety of the device10 lies substantially within the plane “B”. The device 10 reverts fromits temporary shape to its permanent shape by collapsing upon itself orshrinking towards the plane “B”.

Shape memory polymers are a class of polymers that, when formed into anobject such as a wound closure device 10, can be temporarily deformed bymechanical force and then caused to revert back to an original shapewhen stimulated by energy, such as heat or light. Shape memory polymersexhibit shape memory properties by virtue of at least two phaseseparated microdomains in their microstructure. The first domain iscomposed of hard, covalently cross-linked or otherwise chainmotion-limiting structures, which act as anchors to retain the object'soriginal shape. The second domain is a switchable soft structure, whichcan be deformed and then fixed to obtain a secondary or temporary shape.

In the case of heat stimulated shape memory polymers, a transitiontemperature (T_(Trans)) exists at which a shape memory material changesfrom its primary shape to the temporary shape. A permanent temperature(T_(perm)) also exists at which the shape memory material reverts fromthe temporary shape to the permanent shape. In one embodiment, thepermanent temperature (T_(perm)) is within the range of normal bodytemperatures, such that once the device 10 is fully inserted between thetissue segments, the device 10 automatically reverts back to itspermanent shape, i.e., the second, collapsed configuration due to thetemperature of the surrounding tissue segments. In embodiments in whicha higher shape memory temperature is desired, heating can beaccomplished by using a gas or liquid heating medium, heating devices,ultrasonic waves, electrical induction, chemical reaction, and the like.The means for this heating, however, is not limited. Of course, in anapplication involving a living body, care must be taken to utilize aheating temperature which will not cause burns. Examples of liquidheating media include, physiological saline solution, alcohol,combinations thereof, and the like.

Additionally, it is also envisioned that the shape memory material mayrecover its permanent shape upon contacting bodily fluids, such that thedevice 10 reverts to its second, collapsed configuration upon contactingbodily fluids emanated from the tissue segments after being fullydeployed in the wound gap “G”.

In embodiments, the shape memory material is a crosslinked polyurethanemade by using excess diisocyanate or by using a crosslinker such asglycerin or trimethylol propane. Other suitable non-degradable materialsinclude, but are not limited to, polyolefins such as polyethylene(including ultra high molecular weight polyethylene) and polypropyleneincluding atactic, isotactic, syndiotactic, and blends thereof;polyethylene glycols; polyethylene oxides; ultra high molecular weightpolyethylene; copolymers of polyethylene and polypropylene;polyisobutylene and ethylene-alpha olefin copolymers; fluorinatedpolyolefins such as fluoroethylenes, fluoropropylenes, fluoroPEGSs, andpolytetrafluoroethylene; polyamides such as nylon, Nylon 6, Nylon 6,6,Nylon 6,10, Nylon 11, Nylon 12, and polycaprolactam; polyamines;polyimines; polyesters such as polyethylene terephthalate, polyethylenenaphthalate, polytrimethylene terephthalate, and polybutyleneterephthalate; polyethers; polytetramethylene ether glycol;polybutesters, including copolymers of butylene terephthalate andpolytetramethylene ether glycol; 1,4-butanediol; polyurethanes; acrylicpolymers; methacrylics, vinyl halide polymers and copolymers such aspolyvinyl chloride; polyvinyl alcohols; polyvinyl ethers such aspolyvinyl methyl ether; polyvinylidene halides such as polyvinylidenefluoride and polyvinylidene chloride; polychlorofluoroethylene;polyacrylonitrile; polyaryletherketones; polyvinyl ketones; polyvinylaromatics such as polystyrene; polyvinyl esters such as polyvinylacetate; copolymers of vinyl monomers with each other and olefins suchas ethylene-methyl methacrylate copolymers; acrylonitrile-styrenecopolymers; ABS resins; ethylene-vinyl acetate copolymers; alkyd resins;polycarbonates; polyoxymethylenes; polyphosphazine; polyimides; epoxyresins; aramids; rayon; rayon-triacetate; spandex; silicones; andcopolymers and combinations thereof.

FIG. 7A illustrates another embodiment of the wound closure device 20 inwhich a suture “S” is predisposed within the tubular collapsible member200. A helical passage 260 is formed between the outer wall 211 and theinner wall 212 of the member 200. The helical passage 260 stretches fromthe proximal end 210 to the distal end 220 of the member 200 with anopening 261 at the proximal end 210. The suture “S” is disposed withinthe helical passage 260 with a distal end secured to the distal end 220and a proximal end reaching proximally beyond the opening 261 of thepassage 260. An application of force on the proximal end of the suture“S” in the proximal direction pulls out a certain amount of the suture“S” from the helical passage 260. As a result of pulling the suture “S”,a lesser amount of the suture “S” is left in the passage 260 as seen inFIG. 7C. Due to this application of force, the device 200 transits fromits first, expanded configuration shown in FIG. 7A to its second,collapsed configuration shown in FIG. 7C.

With reference to FIGS. 7B and 7D, during operation, after the device 20is fully deployed into the wound gap “G” and after the barbs 230penetrate into the tissue segments “T1” and “T2”, pulling the suture “S”in a proximal direction completes the closure of the gap “G”.

In another alternate embodiment of the wound closure device 30 asillustrated in FIGS. 8A-8B, the device 30 is operatively connected to avacuum “V” which operates to evacuate air from the hollow bore 340 toachieve the result of completely diminishing the hollow bore 340 andsimultaneously transiting the tubular collapsible member 300 from itsfirst, expanded configuration shown in FIG. 8A to its second, collapsedconfiguration shown in FIG. 8B. In such an embodiment, the proximal end310 and the distal end 320 of the tubular collapsible member 300 may beclosed by a proximal cover 311 and a distal cover 321, respectively. Assuch, the covers 311, 321 together with the inner wall of the tubularcollapsible member 300 define a confined space within the member 300.The covers 311 and 321 may be integrated with the member 300 or may beseparate components releasably attached to the member 300. The covers311 and 321 may comprise resilient, semi-resilient, compressible, andflexible type material, and may also comprise shape memory material asdiscussed earlier. The vacuum “V” applies negative pressure to thehollow bore 340 through a conduit 360. In one embodiment, the conduit360 is connected an opening 350 defined through the inner wall and theouter wall of the member 300, such that air is withdrawn from the hollowbore 340 through the opening 350 and the conduit 360 into the vacuum“V”. Alternately, other mechanisms of connecting the vacuum “V” to themember 300 are envisioned.

While several embodiments of the disclosure have been shown in thedrawings and/or discussed herein, it is not intended that the disclosurebe limited thereto, as it is intended that the disclosure be as broad inscope as the art will allow and that the specification be read likewise.Therefore, the above description should not be construed as limiting,but merely as exemplifications of particular embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

1-14. (canceled)
 15. A wound closure device for closing a wound gap, thewound closure device comprising: a collapsible member defining alongitudinal axis and having an outer surface; and tissue engagingstructure supported on the outer surface of the collapsible member, thetissue engaging structure being configured to engage tissue to anchorthe collapsible member to the tissue; wherein the collapsible member isdimensioned to be received within the wound gap such that the tissueengaging structure engages the tissue defining the wound gap, thecollapsible member defining a first configuration and a secondconfiguration and being selectively movable from the first configurationto the second configuration to close the wound gap.
 16. The woundclosure device according to claim 15, wherein the wound closure deviceis fabricated from a shape memory material.
 17. The wound closure deviceaccording to claim 16, wherein the collapsible member is formed frommaterial that transitions from the first configuration to the secondconfiguration at a predetermined temperature.
 18. The wound closuredevice according to claim 16, wherein the collapsible member is formedof material that transitions from the first configuration to the secondconfiguration when contacting a predetermined fluid.
 19. The woundclosure device according to claim 15, wherein the tissue engagingstructure comprises a plurality of barbs configured to penetrate thetissue.
 20. The wound closure device according to claim 19, wherein theplurality of barbs are configured to flex upon contacting the tissueduring movement of the collapsible member in an insertion direction intothe wound gap.
 21. The wound closure device according to claim 19,wherein the plurality of barbs define a first angle with respect to thelongitudinal axis of the collapsible member before contacting thetissue.
 22. The wound closure device according to claim 21, wherein theplurality of barbs define a second angle with respect to thelongitudinal axis upon contacting the tissue when the collapsible memberenters the wound gap and is advanced in an insertion direction.
 23. Thewound closure device according to claim 22, wherein the first angle isdifferent from the second angle.
 24. The wound closure device accordingto claim 22, wherein the plurality of barbs return to the first anglewith respect to the longitudinal axis upon an application of force in adirection opposite to the insertion direction.
 25. The wound closuredevice according to claim 15, wherein the tubular collapsible member isoperatively connected to a vacuum such that the vacuum facilitates thetransition of the collapsible member from the first configuration to thesecond configuration.
 26. The wound closure device according to claim15, further comprising a suture disposed in the collapsible member. 27.The wound closure device according to claim 26, wherein the collapsiblemember defines a helical passage extending from a distal end of thecollapsible member to a proximal end, and the suture is accommodatedwithin the helical passage.
 28. The wound closure device according toclaim 27, wherein the suture is movable within the helical passage uponan application of force on the suture to effect movement of thecollapsible member from the first configuration to the secondconfiguration.
 29. The wound closure device according to claim 15,wherein the collapsible member is tubular.
 30. The wound closure deviceaccording to claim 29, wherein the collapsible member defines a hollowbore that is open in the first configuration and closed in the secondconfiguration.